2¼ cups all-purpose flour
1 tablespoon sugar
½ teaspoon salt
1 cup (2 sticks) cold unsalted butter, cut into small pieces
2 teaspoons raspberry vinegar
6 tablespoons ice cold water
In a large bowl, whisk together the flour, sugar and salt. Using a bench scraper or your fingertips, cut in the butter pieces until the mixture is crumbly with pieces of butter about the size of a pea. Combine the vinegar with the water. Gradually add the liquid to the flour/butter mixture, tossing it until the dough is somewhat shaggy and just holds together. Turn the dough out onto a lightly floured sheet of parchment paper, gather it into two discs, flatten them slightly and wrap each in plastic wrap. Refrigerate for at least one hour before rolling out. Roll out one disc of dough to a thickness of about ⅛" and place it in a 9" pie plate. Roll and crimp the edges. Refrigerate the bottom crust. (Save the second disc of dough for another time. It will keep, wrapped and refrigerated for several days, otherwise, double wrap and freeze it.)
Brown Sugar Cardamom Crumb (adapted from Melissa Clark)
⅓ cup dark brown sugar
⅓ cup granulated sugar
1 teaspoon cinnamon
¾ teaspoon freshly ground cardamom
⅛ teaspoon salt
1 tablespoon orange zest
½ cup melted, unsalted butter
1¾ cups cake flour
In a large bowl, whisk together the brown and granulated sugar, cinnamon, cardamom, salt, and zest. Stir in the melted butter, combining well. Gradually add the cake flour, (I like to sift it in using a fine mesh strainer) using a wooden spoon or a rubber spatula to incorporate. Use your fingers to break up the mixture into large, uniform crumbs. Cover and refrigerate while you prepare the filling.
Raspberry Rhubarb filling
(You can use fresh or frozen fruit; if using frozen raspberries, fold them in at the end to avoid breaking them up. If using frozen rhubarb, lay it out on paper towels; remove any large ice crystals, dab away any excess moisture, but do not defrost it.)
1 pound fresh or frozen rhubarb, rinsed, leaves removed, cut into ½" pieces (about 2½ cups)
2½ cups fresh raspberries
½ cup granulated sugar
½ cup dark brown sugar
2 teaspoons orange zest
pinch of freshly grated nutmeg
¼ teaspoon freshly ground cardamom
3 tablespoons instant tapioca, finely ground
1 tablespoon fresh orange juice
Preheat the oven to 425 degrees F.
In a medium bowl, whisk together the sugar, orange zest, salt, nutmeg, cardamom and tapioca. Place the rhubarb in a large bowl. Add the sugar mixture, tossing to coat. Gently fold in half of the raspberries; reserve the remaining raspberries. Turn the filling into the bottom crust and add the remaining raspberries. Sprinkle the orange juice over the fruit.
Retrieve the crumb from the refrigerator. Sprinkle the crumbs evenly over the filling. Place the pie on a parchment lined baking sheet.
Bake on the bottom rack of the oven for 20 minutes until the crust is set and begins to turn golden. Reduce the oven temperature to 375 F. Move the pie on its baking sheet to the middle rack and bake for an additional 45-50 minutes, covering the edges with strips of aluminum foil to prevent over browning. The crust should be toasty brown; if it is getting too brown towards the last 15 minutes of baking, cover it with a circle of parchment paper. The juices should bubble thickly around the edges and in the middle. Remove from the oven and set on a rack to cool for at least 3 hours before slicing. Wrap and refrigerate any leftovers.